A variety of medicine packing apparatus are available for individually packaging each dose (single packet) of medications such as tablets or powders as per prescription, and for producing the packaged medicines continuously. Among them is a device using rolls wherein a long and narrow packaging sheet is pre-folded in two in the length direction. Generally, in the packaging unit of this type of medicine packing apparatus, the packaging sheet is fed from the roll, and following printing of necessary information with a printer, the packaging sheet is opened from the folded state, and a single dosage of medication is injected from the nozzle of a hopper inserted in this opening. Subsequently, the packaging sheet is sealed (heat sealed) in a heat sealing section so as to seal the medication.
For example, Patent document 1 discloses a medicine packing apparatus in which a pair of first rotating shafts is provided in a direction (hereafter referred to as transverse direction) perpendicular to the conveying direction of the packaging sheet, a transverse sealer for sealing the packaging sheet in transverse direction is provided in this pair of first rotating shafts, a second rotating shaft is provided coaxially with each first rotating shaft, and a longitudinal sealer for sealing the packaging sheet in the conveying direction (hereinafter referred to as vertical direction) is provided in this second rotating shaft so that sealing of the packages can be done at once. In this medicine packing apparatus, it is possible to adjust the size of the sachet as per the supply amount of medication by controlling the drive of the second rotating shaft provided with the longitudinal sealer, and adjusting a conveyance rate of the packaging sheet, for example, by varying a conveyance speed.
However, in the medicine packing apparatus disclosed in Patent document 1: Japanese Patent Publication No. 2942769, a heater is housed in the first rotating shaft, heat from this heater is conveyed to the transverse sealer of the first rotating shaft, and further conveyed from the first rotating shaft to the longitudinal sealer of the second rotating shaft, and therefore, there was a drawback of a large temperature difference between the transverse sealer and longitudinal sealer. There was also an issue such that, because the intervals at which the longitudinal sealer contacts the packaging sheet and the intervals at which the transverse sealer contacts the packaging sheet were different, the timings of heat transferred from the respective sheet sections to the packaging sheet were different, and a temperature difference between the transverse sealer and longitudinal sealer becomes all the more larger. Accordingly, it was necessary to use an expensive packaging sheet wherein a difference between the fusion temperature and heat resistance temperature is large, resulting in an increase in cost of the packaging sheet. In addition, there was also a drawback of the structure becoming complicated because the first rotating shaft provided with a heat sealing part and the second rotating shaft provided with a longitudinal sealer were driven by separate drive mechanisms.